Spinal disorders such as degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvature abnormalities, kyphosis, tumor, and fracture may result from factors including trauma, disease and degenerative conditions caused by injury and aging. Spinal disorders typically result in symptoms including pain, nerve damage, and partial or complete loss of mobility.
Non-surgical treatments, such as medication, rehabilitation and exercise can be effective, however, may fail to relieve the symptoms associated with these disorders. Surgical treatment of these spinal disorders include discectomy, laminectomy, fusion and implantable prosthetics. As part of these surgical treatments, connecting elements such as vertebral rods are often used to provide stability to a treated region. During surgical treatment, one or more rods may be attached to the exterior of two or more vertebral members.
Rods redirect stresses away from a damaged or defective region while healing takes place to restore proper alignment and generally support the vertebral members. In some applications, rods are attached to the vertebral members without the use of implants or spinal fusion. Flexible connecting elements are also known that permit limited spinal motion of a spinal motion segment. Such flexible connecting elements can provide dynamic spinal support.
Vertebral rods and their component parts can be manufactured employing, for example, molds, dies, machining and extrusion methods. In some cases, these manufacturing methods can undesirably alter the shape and/or dimension of the contemplated rod design. For example, during manufacture employing injection molding, the molded part can suffer from warping, shrinkage and creep.
Therefore, it would be desirable to provide a vertebral rod configured to provide structural and dimensional stability during manufacturing and assembly of the vertebral rod and its component parts. Desirably, the vertebral rod includes a stability element, at least a portion of which being removable from the vertebral rod, which avoids undesirable or unintended alteration of rod shape and dimension to preserve the integrity of the vertebral rod design. It would also be desirable if such a vertebral rod system includes a guide element to facilitate assembly of components of the vertebral rod.